The average market price for a group of price risk forward or futures contracts, such as gas futures contracts.

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Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Nominal mass used to calculate payments on a derivative instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

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Financial Instruments (Unsettled Derivatives) (Details) oz in Thousands, lb in Millions, $ in Millions			3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) lb oz $ / lb $ / oz	Mar. 31, 2019 lb $ / lb $ / lb	Jun. 30, 2019 USD ($) $ / lb $ / oz	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) $ / lb $ / oz	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 42		$ 42		$ 42		$ 23
Derivative Liability, Fair Value, Gross Liability	56		56		56		48
Derivative Asset, Fair Value, Gross Liability	5		5		5		7
Derivative Liability, Fair Value, Gross Asset	5		5		5		7
Derivative Asset	37		37		37		16
Derivative Liability	51		51		51		41
Trade accounts receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	26		26		26		3
Derivative Liability	22		22		22		24
Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Asset	11		11		11		13
Derivative Liability	29		29		29		17
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net			(3)	$ 0	(1)	$ 2
Derivative Asset, Fair Value, Gross Asset	1		1		1		0
Derivative Liability, Fair Value, Gross Liability	5		5		5		9
Derivative Asset, Fair Value, Gross Liability	1		1		1		0
Derivative Liability, Fair Value, Gross Asset	1		1		1		0
Derivative Asset	0		0		0		0
Derivative Liability	4		4		4		9
Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	41		41		41		23
Derivative Liability, Fair Value, Gross Liability	51		51		51		39
Derivative Asset, Fair Value, Gross Liability	4		4		4		7
Derivative Liability, Fair Value, Gross Asset	4		4		4		7
Derivative Asset	37		37		37		16
Derivative Liability	47		47		47		32
Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1		1		1		0
Derivative, Nonmonetary Notional Amount, Mass \| lb		74
Derivative, Average Forward Price \| $ / lb		2.76
Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	41		41		41		23
Derivative Liability, Fair Value, Gross Liability	51		51		51		39
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb		2
Derivative, Average Forward Price \| $ / lb		2.66
Future [Member] \| Not Designated as Hedging Instrument [Member] \| FMC's Copper Futures and Swap Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 5		$ 5		$ 5		$ 9
Copper \| Short [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / lb	2.72		2.72		2.72
Derivative, Nonmonetary Notional Amount, Mass \| lb	505
Derivative, Average Forward Price \| $ / lb	2.79		2.79		2.79
Copper \| Long [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / lb	2.72		2.72		2.72
Derivative, Nonmonetary Notional Amount, Mass \| lb	86
Derivative, Average Forward Price \| $ / lb	2.83		2.83		2.83
Gold \| Short [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / oz	1,416		1,416		1,416
Derivative, Nonmonetary Notional Amount, Mass \| oz	74
Derivative, Average Forward Price \| $ / oz	1,328		1,328		1,328
Sales [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			$ (109)	(44)	$ 11	(161)
Sales [Member] \| Copper \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			(122)	(14)	0	(149)
Sales [Member] \| gold and other [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			13	(30)	11	(12)
Cost of Sales [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net			$ (4)	$ 6	$ (3)	$ 8